1. Field of the Invention
This invention relates to heat exchangers, and more particularly, to a method of repairing a tube in a heat exchanger.
2. Description of the Prior Art
Heat exchangers formed from a plurality of tubes have traditionally been susceptible to developing leaks in one or more tubes, and since the processes in which heat exchangers are utilized generally require separation of the primary and secondary fluids, leaky tubes are normally removed from service by inserting a tapered plug and driving it into the end of a tube with a hammer or, more recently, by utilizing welding, includng explosive welding, to weld a plug in a tube.
When leaks occur in straight tube heat exchangers, the tubes can often be replaced; however, when the heat exchanger is formed from a plurality of U-shaped tubes, replacing a single tube becomes more of a problem, and in some cases, impossible without removing several tubes.
Tube failures often occur in or near the tube sheet; therefore, to learn the nature of the defect causing the failure, it is desirable to remove the tube or at least a portion of the tube so that it may be inspected and tested in order to learn as much as possible about the cause of the failure.